Chitosan and Laminarin as Alternatives to Copper for Plasmopara viticola Control: Effect on Grape Amino Acid.

Copper fungicide use is limited by the European regulation; therefore, new strategies have been developed to prevent grapevine downy mildew (GDM). However, there is poor information about their effects on grape amino acid composition. This field trial aimed to evaluate the effect on grape amino acid composition of chitosan and of a mixture of laminarin and Saccharomyces extracts (LamE), applied in different strategies with copper hydroxide. The results showed that all the treatments applied to grapevines decreased the concentration of several amino acids. Moreover, treatments that have mostly decreased these compounds are those with copper hydroxide, especially when applied individually. LamE applied individually or alternately with copper hydroxide had the least negative effect on grape amino acid content. These results provide further information about the negative effects of copper on grape quality, which can be reduced when it is used in strategy with LamE or chitosan in GDM control.

An engineered co-sensitization system for highly efficient dye solar cells.

Novel co-sensitizers have been structurally tailored and implemented in multi-sensitized devices demonstrating synergic efficiency enhancement attributable to improved light-harvesting as well as prevention of charge recombination.

Preharvest Fungicide, Potassium Sorbate, or Chitosan Use on Quality and Storage Decay of Table Grapes.

Potassium sorbate, a program of four fungicides, or one of three chitosan formulations were applied to clusters of 'Thompson Seedless' grape berries at berry set, pre-bunch closure, veraison, and 2 or 3 weeks before harvest. After storage at 2°C for 6 weeks, the natural incidence of postharvest gray mold was reduced by potassium sorbate, the fungicide program, or both together in a tank mixture, in 2009 and 2010. In 2011, the experiment was repeated with three chitosan products (OII-YS, Chito Plant, and Armour-Zen) added. Chitosan or fungicide treatments significantly reduced the natural incidence of postharvest gray mold among grape berries. Berries harvested from vines treated by two of the chitosan treatments or the fungicide program had fewer infections after inoculation with Botrytis cinerea conidia. None harmed berry quality and all increased endochitinase activity. Chitosan decreased berry hydrogen peroxide content. One of the chitosan formulations increased quercetin, myricetin, and resveratrol content of the berry skin. In another experiment, 'Princess Seedless' grape treated with one of several fungicides before 4 or 6 weeks of cold storage had less decay than the control. Fenhexamid was markedly superior to the other fungicides for control of both the incidence and spread of gray mold during storage.

Genetic variability of the stolbur phytoplasma vmp1 gene in grapevines, bindweeds and vegetables.

AIM: Evaluation of the genetic variability of stolbur phytoplasma infecting grapevines, bindweeds and vegetables, collected in different central and southern Italian regions. MATERIALS AND RESULTS: Phytoplasma isolates belonging to stolbur subgroup 16SrXII-A were subjected to molecular characterization by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP), to investigate two different nonribosomal genes: tuf and vmp1. In grapevines, 32% of samples were infected by tuf-a type and 68% by tuf-b type, with different relative incidences in the regions surveyed. All herbaceous samples (bindweeds, tomato, tobacco, pepper, celery) were infected by tuf-b. The gene vmp1 showed higher polymorphism in grapevines (nine profiles) than herbaceous plants (six) by RFLP analysis, in agreement with nucleotide sequences' analysis and virtual digestions. CONCLUSIONS: The phylogenetic analysis of vmp1 gene sequences supports the RFLP data and demonstrates the accuracy of RFLP for preliminary assessments of genetic diversity of stolbur phytoplasmas and for screening different vmp types. SIGNIFICANCE AND IMPACT OF THE STUDY: Stolbur represents a serious phytosanitary problem in the areas under investigation, owing to heavy economic losses in infected grapevines and vegetables. Molecular information about the complex genotyping of the vmp1 gene provides useful data towards a better understanding of stolbur epidemiology. Moreover, this study clarifies some different vmp1 genotype classifications of stolbur, providing molecular data in comparison with previous investigations.

Gray Mold Infection of Actinidia arguta in Italy.

Gray mold is caused by Botrytis cinerea Pers.:Fr., a cosmopolitan and polyphagous fungus that is responsible for significant losses on several fruit crops, including kiwifruit (Actinidia deliciosa), in the field and during storage (2). A. arguta, the hardy kiwifruit, is grown in several countries (e.g., Japan, China, Korea, Russia, and the United States) (1,3) and regions of Italy (Apulia [southeastern], Basilicata [southern], Marche [central eastern], Tuscany [central western], and Piedmont, Friuli Venezia Giulia, and Trentino Alto Adige [northern]) (4). The oblong- to oval-shaped fruit is produced in clusters, has a smooth, edible, thin skin, bears tips with a persistent style, and weighs approximately 5 to 15 g (1,3,4). Several fruits of cv. Ananasnaya selection 'Anna red' harvested from September to October in 2007 and 2008 in the Apulia and Marche regions showed browning and depressions in the surface and a decay of the flesh. Disease affected approximately 5% of 420 examined fruits; symptoms mainly developed in the equatorial zone, eventually expanding through the entire fruit. Severely infected fruit showed deformation followed by drying. In the field or after storage in an environment with high relative humidity, fungal mycelia with sporulation appeared on the surface of the symptomatic areas of the fruit. Nineteen symptomatic fruit were surface disinfested by immersion in a 0.5% sodium hypochlorite solution for 2 min, then rinsed in sterile distilled water. Portions of the flesh were plated onto petri dishes containing potato dextrose agar (PDA) supplemented with 250 mg/liter of each ampicillin and streptomycin sulfate. Colonies that originated from symptomatic portions of the fruit were transferred to new PDA plates and identified as B. cinerea by the morphological features of conidiophores and conidia. Conidia were produced on dichotomously branched conidiophores, which had globose basal cells from mycelia. The conidia were hyaline or pigmented, ellipsoid-obovoid, globoid, and without septa (2). Conidia were collected from an isolate (Accession No. CBS 125087) of B. cinerea recovered from diseased A. arguta fruit grown in Monopoli (BA), Apulia in September 2007, and maintained in pure culture on PDA. A spore suspension was created by flooding plates with a small volume of sterile distilled water plus surfactant (0.05% Triton X-100). The suspension was filtered through four layers of cheesecloth and diluted with sterile water to an absorbance of 0.25 at 425 nm as determined by a spectrophotometer. This suspension contained approximately 1.0 × 106 conidia/ml and was diluted with sterile water to 1 × 104 spores/ml. Twenty microliter droplets of spore suspension were deposited within the equatorial zone on each of 10 nonwounded fruits of cv. Ananasnaya selection 'Anna red'. All fruit developed typical gray mold symptoms after 4 to 5 days of incubation at 20 ± 2°C and 95 to 98% relative humidity. Reisolation from the decayed tissues on PDA produced pure colonies of B. cinerea. To our knowledge, this is the first report of B. cinerea infection on A. arguta in Italy. References: (1) C. L. Fisk et al. Postharvest Biol. Technol. 47:338, 2007. (2) T. Michailides and P. A. G. Elmer, Plant Dis. 84:208, 2000. (3) J. Morton. Page 293 in: Fruits of Warm Climates. J. F. Morton, Miami, FL, 1987. (4) R. Testolin and G. Costa. Frutticoltura 56:31, 1994.

Exogenous mesenchymal stem cells localize to the kidney by means of CD44 following acute tubular injury.

Mesenchymal stem cells (MSC) were recently shown to migrate to injured tissues when transplanted systemically. The mechanisms underlying the migration and homing of these cells is, however, unclear. In this study, we examine the role of CD44 and its major ligand, hyaluronic acid, in the trafficking of intravenously injected MSC in the glycerol-induced mouse model of acute renal failure (ARF). In vitro, hyaluronic acid promoted a dose-dependent migration of the stem cells that was inhibited by an anti-CD44 blocking monoclonal antibody. In vivo, stem cells injected into mice with ARF migrated to the injured kidney where hyaluronic acid expression was increased. Their presence correlated with morphological and functional recovery. Renal localization of the MSC was blocked by pre-incubation with the CD44 blocking antibody or by soluble hyaluronic acid. Stem cells derived from CD44 knockout mice did not localize to the injured kidney and did not accelerate morphological or functional recovery. Reconstitution by transfection of CD44 knockout stem cells with cDNA encoding wild-type CD44, but not a loss of function CD44 unable to bind hyaluronic acid, restored in vitro migration and in vivo localization of the cells to injured kidneys. We suggest that CD44 and hyaluronic acid interactions recruit exogenous MSC to injured renal tissue and enhance renal regeneration.

Antiangiogenic and immunomodulatory effects of rapamycin on islet endothelium: relevance for islet transplantation.

Donor intra-islet endothelial cells contribute to neovascularization after transplantation. Several factors may interfere with this process and ultimately influence islet engraftment. Rapamycin, a central immunosuppressant in islet transplantation, is an mTOR inhibitor that has been shown to inhibit cancer angiogenesis. The aim of this study was to evaluate the effects of rapamycin on islet endothelium. Rapamycin inhibited the outgrowth of endothelial cells from freshly purified human islets and the formation of capillary-like structures in vitro and in vivo after subcutaneous injection within Matrigel plugs into SCID mice. Rapamycin decreased migration, proliferation and angiogenic properties of human and mouse islet-derived endothelial cell lines with appearance of apoptosis. The expression of angiogenesis-related factors VEGF, alphaVbeta3 integrin and thrombospondin-1 on islet endothelium was altered in the presence of rapamycin. On the other hand, rapamycin decreased the surface expression of molecules involved in immune processes such as ICAM-1 and CD40 and reduced the adhesion of T cells to islet endothelium. Our results suggest that rapamycin exerts dual effects on islet endothelium inducing a simultaneous inhibition of angiogenesis and a down-regulation of receptors involved in lymphocyte adhesion and activation.

Preharvest Chitosan and Postharvest UV Irradiation Treatments Suppress Gray Mold of Table Grapes.

The effectiveness of chitosan treatment of table grapes, alone or in combination with ultraviolet-C (UV-C) radiation, to control postharvest gray mold caused by Botrytis cinerea, was determined in California, United States. The influence of these treatments on catechin and resveratrol contents and chitinase activity in grape berry skins also was assessed. Clusters of cvs. Thompson Seedless, Autumn Black, and Emperor were sprayed in the vineyard with 1% chitosan, then harvested daily for 5 days. Promptly after harvest, they were inoculated with B. cinerea. Decay incidence and disease severity were significantly reduced by chitosan, which was most effective on berries harvested 1 or 2 days after treatment. In another experiment, grape berries were sprayed in the vineyard with chitosan, harvested 2 days later, irradiated for 5 min with UV-C (0.36 J/cm2), and inoculated with B. cinerea 2 days later. Combined chitosan and UV-C treatments applied to cv. Autumn Black or selection B36-55 were synergistic in reducing gray mold incidence and severity compared with either treatment alone. Preharvest chitosan treatment increased neither concentration of catechin or resveratrol nor activity of chitinase in berry skin. Conversely, UV-C irradiation, alone or combined with chitosan treatment, induced catechin in cv. Autumn Black berries and trans-resveratrol in both cv. Autumn Black and selection B36-55.

Decreased cannabinoid CB1 receptor mRNA levels and immunoreactivity in pituitary hyperplasia induced by prolonged exposure to estrogens.

Recent studies have demonstrated that cannabinoid CB1 receptor gene expression in the anterior pituitary gland is under the influence of estrogens. Because these receptors have been recently involved in the development of several types of cancer, it would be interesting to examine the changes produced in these receptors by the development of pituitary hyperplasia after a chronic exposure to estrogens. To this end, we measured mRNA levels and immunoreactivity for the CB1 receptor in the anterior pituitary gland of rats implanted with silastic capsules containing diethylstilbestrod (DES), a synthetic estrogen, or empty capsules. Results were as follows. Induction of pituitary hyperplasia with DES produced the expected body weight loss (-38.4%) and increase in pituitary weight (5-fold) and plasma prolactin (PRL) levels (90-fold). In hyperplastic pituitaries, both CB1 receptor mRNA levels and immunoreactivity decreased significantly (-79.4% and -63.2% respectively). Double immuno-labelling studies demonstrated that CB1 receptors colocalized, in hyperplastic pituitaries, with PRL- or luteinizing hormone-containing cells, as they did in normal pituitaries. In summary, estrogen-induced pituitary hyperplastia was associated with a marked reduction in CB1 receptors, despite the fact that these receptors were located, among others, on lactotroph cells which develop hyperplasia during DES exposure. Whether this decrease is involved in the ethiology of pituitary hyperplasia and whether the pharmacological activation of these receptors might affect this process are presently unknown, but this will be subjected of further research.